Surveying instrument.



W. Nl MOGOWAN.

SURVEYING INSTRUMENT.

APPLICATION FILED DBG.13,1911.

Paten-ned 001221912.

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sUnvErIue msraUMENT.

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Specication of Letters Patent.

Patented ct. 22, 1912.

Application led December 13, 1911. Serialv No. 665,470.

To all whom 'it may concern:

Be it known that I, WILLIAM N. MC- GowAN, a citizen of the UnitedStates, residing at Croatan, in the county of Craven and State of NorthCarolina, have invented new and useful Improvements in SurveyingInstruments, of which the following is a specification.

The invention'relates to a surveyingiinstrument, and more particularlyto the class of hydrostatic surveying instrulnents.

.The primary object of the invention is the provision of an instrumentof this character in which grades or levels in ground or other surfacesmay be readily and accurately determined, the instrument being adaptablefor use by bricklayers, masons, carpenters, or other skilled mechanicsfor obtaining accuracy in work.

lAnother object of the invention isf the provision of a surveyinginstrument for use in grading orlaying out level surfaces, so that theuser may survey between any two points on a predetermined grade orlevel, thereby permitting an accurate calculation' of the grade orlevel.

A further object of the invention is the provision of a surveyinginstrument of this character in which the supports therefor may bereadily and easily adjusted, so as to position the instrument in a truevertical position, irrespective of the irregularity in the surface ofthe ground, and that may be fastened to the ground, so as to prevent thepossibility of the falling of the instrument when in use.

A still further object of the invention is the provision of a surveyinginstrument of this character which is simple in construction, reliableand eiiicient in its purpose, and inexpensive in manufacture.'v

With these and other objects in View, the invention consists in theconstruction, combination and arrangement of parts, as will behereinafter more fully described, illustrated in the accompanyingdrawings, and

-pointed out in the claims hereunto appended. v

In the drawings: Figure 1 is a-side elevation of a surveying instrumentconstructed in accordance with the invention, shown applied to a levelsurface. Fig. 2 1s a similar view, showing the same applied to a grade.Fig. 3 is a vertical longitudinal sectional (9 view through theinstrument. Fig. 4 is a sectional view on the. line 4-4 of Fig. 1.

Similar reference characters indicate corresponding parts throughout theseveral vlews ofthe drawings.

Referring to the drawings by numerals, 5 and. 6 designate complementarymeasuring bodles or tubes, the same being preferably constructed fromglass, although they may be made from any other suitable transparentmaterial, if desired, each being formed with a contracted open end 7,throughewhich l1qu1d is introduced therein. These tubes 5 and 6 arepreferably set in frames 8 provlded at their lower ends with adjustablefeet or legs 9, the latter being secured in adjusted position by means.of the usual set screws 10. Thus in this manner the tubes maybearranged vertically, irrespective. of

.the irregularity `in the surface to be measured. Formedcentrally in thelower ends of the frames 9.and. projecting therefrom are 'screws 11,which latter are adapted to engage in the ground or surface to bemeasured, so as to prevent the tilting of the measuring tubes when inuse. Disposed within the tubes 5 and 6 are stationary measuringv stemsl2, the same rising centrally from the bottoms of the tubes and beingcoextensive with the length of the tubes, the said stems 12 beingprovided with measuring'scales 13 on their outer surfaces, so as tocoperate with the columns of liquid rising within the tubes about the.said stems, whereby grades or levels in vsurfaces may be determinedbetween two predetermined points. The zero mark 14 of the scales 13 islocated at a medial point of the stems 12 and the numbers of the saidscales are disposed up and down thereon from the zero point thereof, asis clearly shown.

In the reading of the scales, the liquid rising in either of the tubes 5and 6 above the zero mark indicates the rise in the grade or surface,while the lowering of the liquid in said tubes below the zero markindicates a fall in the surface, the scales 13 being clearlyvisibleexteriorly of the tubes 5 and 6 for the reading thereof.

Formed at the bottoms of the tubes 5 and 6 and projecting outwardly fromone side thereof are nipples 15, to which are con; nected the ends of aieXible tube or pipe 16, which 'establishes communication between thesaid tubes 5 and 6, so that the liquid contained in the said tubes mayfiow from one to the other, during the manipulation of' the instrument.A suiiicient quantity of water is poured into the tubes 5 and 6 toentirely fill the-pipel, and eachV of the tubes partv way, so thatwhen'the tubes stand at the same level, the reading, as indicated by theheight of the water, will be the same in both tubes, but on placing thetubes at predetermined points of the grade, the Water in the lowermosttube Will rise to a greater height than the Water in the higher tube, sothatupon reading of. the scales 13 upon the stems 12, the exact fall inthe grade may be accurately ascertained.

What is claimed is:

1. The combination with transparent liquid containing measuring tubes ofhousings telescoped over and detachably receiving said tubes and eachhaving a slot longitudinally therein to permit7 visual inspection of thecontents of the tube, flexible tubing connecting said first named tubes,an anchoring screw depending centrally from each of the housings andadapted to engage in the ground, slotted slides, set screws passedthrough the slides and engaged in the housings for locking the slidesin'adjust-ed po si tion, and props hinged to the slides.

2. The combination With transparent liquid containing measuring tubes ofhousings l the contents of the tube, flexible tubing con-- necting saidfirst named tubes, an anchoring screw depending centrally from each ofthe vhousings and adapted to engage in the ground, slotted slides, setscrews passed through the slides and engaged in the housings for lockingthe slides in adjusted position, props hinged to the slides, andstationary measuring rods rising centrally interiorly of the first namedtubes from the bottoms thereof and having graduation marks extending inopposite directions from medial points thereof.

ln testimony whereof l aliix my signature in presence of, two Witnesses.

WILLIAM N. MCGOWAN. Witnesses:

J. C. THOMAS, Jr., L. S. WOOD.

